Atoms – Historical Development
To some Greeks, were smallest “indivisible” unit of matter
In 1700’s, 1800’s discovery of chemical “elements” (H, He,
C, O, N, ...)
somehow made of different kinds of atoms
In early 1900’s, parts of atoms and reasons the elements
differ understood
In early to mid 1900’s ways to change one kind of atom into
another understood
radioactive decay
fission
fusion